Design and Development of a Laboratory Scale Biomass Gasifier

A pilot scale biomass gasification facility, whose core is a downdraft throated gasifier with a thermal throughput of 200 kW, was recently installed and started at CRIBE, a university research centre on energy from biomass in Pisa. The facility is equipped with probes and instrumentations for monitoring operating and process variables (e.g. temperatures, pressures, flow rates, compositions). This paper reports the results of a first set of tests, aimed at assessing plant performance using different types of biomass (wood pellets and residues from vegetable oil pressing). These results show that even biomass with characteristics (size, composition) not meeting the design specifications may be processed in the gasifier, provided that adequate control of operations and calibrated mixing of different biomass feeds are ensured.

International journal of energy engineering, 2013

Bio mass gasification to produce combustible gas is one of the pro mising sustainable energy options available for many countries. At present, a few s mall scale co mmun ity based power generation systems using biomass gasifiers are in operation in Sri Lan ka. However, due to insufficient knowledge on the relationships between important parameters, these systems are not operating properly in full capacity. This stands as an obstacle to further expand the use of gasifier technology. Hence, in o rder to imp rove the knowledge of the gasification and to simp lify the process, researches are being carried out to determine the relat ionships between different parameters and to optimize the power generation. The object ive of this study was to identify most influential parameters related to fuel wood gasification using a down draft gasifier to improve the gasification processes. A downdraft gasifier of 10kW electrical capacity was used to study the effect of equivalence ratio (ER) on the ...

Biomass and Bioenergy, 2011

Pumping power Acacia nilotica (L) Producer gas a b s t r a c t When the objective is to generate motive or electric power via I.C. engine, the overall pressure drop through the suction gasification system in addition to gas quality has become a sensitive issue. This work, therefore, presents an experimental study on a suction gasifier (downdraft) arrangement operating on kiker wood or Acacia nilotica (L).

2012

Using biomass gasification to produce combustible gas is one of the promising sustainable energy options available for many countries. At present, a few small scale community based power generation systems using biomass gasifiers are in operation in Sri Lanka. However, due to the lack of proper knowledge, these systems are not being operated properly in full capacity. This stands as an obstacle for further expansion of the use of gasifier technology. The objective of this study was to identify the most influential parameters related to fuel wood gasification with a down draft gasifier in order to improve the gasification processes. A downdraft gasifier of 10kW electrical capacity was used to study the effect of equivalent ratio (Actual air fuel ratio to Stoicheometric air fuel ratio: ER) on the specific gas production, the heating value of gas produced and the cold gas efficiency using three throat diameters (125mm, 150mm and 175mm). Six trials were carried out for each throat diame...

American Journal of Applied Sciences, 2014

Increasing global concern over the environmental issues and depletion of fossil fuels, significant interest has been shown by the researchers to develop alternate energy technologies like biomass, biogas, solar to meet the future energy demand. The prediction of the performance of different biomass energy sources in gasifiers is needed for the implementation of this technology to fulfil the need of decentralized heat and power applications, relevant to remote villages. This study presents the theoretical and experimental studies conducted on a 50 kW downdraft biomass gasifier with various biomass materials such as wood, coconut shell, rubber seed kernel and coir pith which are generally available in villages. Two-zone kinetic equilibrium model approach is used to predict the composition and temperature of the producer gas. The influence of equivalence ratio on the reaction temperature, quality of producer gas and gasifier conversion efficiency are discussed. The experimental and theoretical studies show that the rubber seed kernel can be effectively used as a feedstock of the biomass gasifier to meet the rural energy demand.

International Journal of Engineering, Science and Technology, 2011

Biomass gasifiers of fixed bed, downdraft type are generally used for driving internal combustion engines. As part of research work, a versatile, throat type, biomass gasifier was developed. The gasifier had facilities for bed temperature measurements, pressure measurements, physical observation, sampling of bed particles, bed agitation, etc. The generated producer gas was cleaned and cooled in downstream components namely, cyclone separator, dust filter and gas cooler such that water had no direct contact with producer gas. The dry cleaned producer gas was flared directly at the exit pipe. Bed temperatures and bed char properties viz., weight, volume, density and volatile matter content along the gasifier axis, wood feeding rate, gasification air and producer gas flow rates, etc. were observed and analyzed during the gasification of wood pieces. Temperature stratification was found to depend on biomass bed height, phase of operation, location of reaction zones and reactor pressure. Specific gasification rate for wood pieces was found to be 75 kg h-1 m-2 which was lesser than that for loose bioresidues. Mass balance was also done for the gasification system. The producer gas to wood ratio was determined to be 2.39 at an optimum equivalence ratio of 0.3. The volume of wood piece or char decreased by as high as 86% even before it enters the reduction zone of the gasifier.

Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2024

Rice husk gasification is increasingly attractive, particularly with updraft gasifier type, because of its simple construction and ease of operation. However, updraft gasifier has a disadvantage of generating substantial amounts of tar. Tar will decompose into combustible gas when exposed to high temperatures. The reduction zone has a high temperature for tar decomposition to occur. Therefore, in this research, updraft gasifier was modified by positioning gas outlet at the reduction zone and inducing gasification air supply using a blower. Modifications are made by moving the gas outlet from the top to the middle or reduction area. The initial start-up of the system uses a blown air supply system, then after the syngas are produced by the operation, it is replaced with a sucked air supply. Two blowers are used, namely an exhalation or blowing blower for initial start and a suction blower for continuous operation. The fuel used was low bulk density, specifically rice husks. The aim was to characterize the modified gasifier, focusing on parameters such as operating time, duration of gas combustion, air-to-rice husks ratio, and flame color. Typically, the experiments were conducted under constant of air velocity and fuel quantity. The results showed that the average operating time, duration of flammable gas, and air-to-rice husks ratio were 74.25 minutes, 52.28 minutes, and 7.6 kg air/kg husk, respectively, and the flame produced was a bluish-yellow color that indicates a reduction tar.

MATEC Web of Conferences

A down draft biomass gasifier stove with four steps of cleaning gas system was developed to produce the producer gas for replacing LPG for cooking applications in lunch project for the student in rural school area. This project has been implemented at Bangrakam primary school that located at Pitsanuloke Province, Thailand. The biomass fuels used are Mimosa wood twigs. The gasifier stove was developed based on down draft fixed bed gasifier with the maximum fuel capacity of fourteen kilograms. The performance testing of the biomass gasifier stove showed that the heating value of the producer gas is 4.12 MJ/Nm 3 with the thermal efficiency in the percentage of 85.49. The results from this study imply that it has high potential to replace LPG with producer gas.

Engineering and Technology Research Journal, 2018

The use of biomass is becoming increasingly important as an alternative energy resource, particularly for developing countries. The conversion of solid biomass to gaseous forms by the use of gasifiers has some prospects for domestic and industrial utilization. Improved cook-stoves based on gasification are considered to be costeffective means of energy supply to households for cooking. In this study, four biomass fuelswood chips, corn cobs, coconut shells and palm kernel shellswere characterized and used to carry out a performance evaluation of an inverted downdraft biomass gasifier cook-stove. The performance evaluation showed that all fuels used were suitable for the operation of the cook-stove with wood chips having the best performance. The efficiency of the stove varied with the fuel used with the maximum efficiency of the cook-stove being 20.76%. The fuel consumption rate of the cook-stove for utilization of the biomass fuels ranged between 1.60 to 1.82 kg/hr. The specific gasification rate also ranged between 85.89 and 102.25 kg/m 2 hr.

Asia Pacific Journal of Multidisciplinary Research, 2015

Synthesis gas formation which can be transformed to useful compounds through biomass gasification is perceived as one promising process of biofuel production. A construction, design and development of an efficient and small-scale wood-fired gasifier prototype was made at Batangas State University. This study included the costs and specifications of materials, the design, components and percent conversion of the biomass to syngas by obtaining the amount of the residue. Set of operating conditions were determined so as to achieve a good performance of the gasifier; otherwise it adversely affected the operation of the prototype. The gasifier operates in a condition in which the air flow rate is 560-610 cm 3 /min wherein the valve is half-open and the blower is turned on after 20 seconds. The gasifier will be closed after a minute of start-up. With these conditions, the gasifier works accordingly to a smooth operation. Syngas was composed of methane (2.32 % volume), carbon dioxide (10 % volume), carbon monoxide and minimal amount of hydrogen. Two (2) kg of woodchips with 90.75% conversion was the best amount of feed suited for the operation of the gasifier. This innovation comprises a method which efficiently converts the feedstock thereby enhancing the energy of the syngas produced with by-products at minimum acceptable value. The wood-fired gasifier will be a very helpful tool in contributing to the resolution of pressing social and environmental problems such as energy security and local agricultural waste pollution.